SIPTU want an urgent meeting with management at Aer Lingus after the announcement it plans to lay off 500 staff.
The airline says the job losses are due to Covid-19, which it says is having a catastrophic effect on the aviation industry.
Last night, the Transport Minister Shane Ross urged both the unions and the company to engage in constructive talks.
Neil McGowan, SIPTU's Aviation Sector Organiser says the discussions need to begin immediately.
Mr McGown says: "The company are legally obliged to enter into a 30-day consultation process.
"So we are calling for an immediate engagement. We hope that will happen in the coming days.
"That needs to take the form of union officials and the elected representatives on the ground in the airport."